1. Field of the Invention
The present invention relates to rapid response fire fighting equipment, and more particularly to a portable water and chemical foam applicator for marine or shipboard use.
2. Description of the Prior Art
Most fire fighting equipment found aboard ship uses foam produced by mixing water with a chemical foam concentrate. Sometimes water alone is sufficient for a particular fire, but the foam produced by mixing water with the foam concentrate is usually much more effective because it not only knocks down a fire but follows up by smothering it. However, this happy result occurs only if there is an immediate and ample supply of foam at the fire scene. Failing this, it will be only a matter of minutes if not seconds before the fire generates temperatures so high that the resultant rapidly moving flame front quickly places the fire out of control.
Water and foam systems used by most large commercial and U.S. Navy ships generally fall into one or more of the following categories:
1) so-called in-line foam generating and mixing equipment that is fixed or permanently installed in position. This type of equipment can produce relatively large quantities of foam, but because it is fixed in position it can deliver the foam to remotely located sites only through long foam supply hoses. Hoses take a significant amount of time to unreel and deploy, and they clutter the fire scene;
2) self-contained and portable equipment mounted on a cart or other vehicle for movement to the fire scene. This type of equipment can only transport a limited quantity of foam concentrate. It also has the disadvantage that it takes time to reach the scene, unreel and deploy the foam applicator hoses, connect fire hoses to the equipment, operate the foam mixture apparatus, and pump the mixture to the fire scene through the foam applicator hoses;
3) a third system is extremely portable and can be deployed to locations not easily reached by carts or the like, nor by long hoses connected to in-line equipment, carts or other wheeled equipment. The foam concentrate is placed in a reservoir of some kind that is mounted or strapped onto a person, and the person can then simply walk to the scene of the fire. Although the storage capacity of these body mounted foam applicators is much less than that of the systems referred to earlier, they can be immediately deployed. They are also flexible in the sense that a person wearing the foam applicator can move wherever the rapidly changing character of a fire requires. U.S. Pat. Nos. 5,445,226 (Scott et al), 2,044,687 (Hatten), and 4,688,643 (Carter et al) disclose such equipment worn as a back pack.
This type of body mounted equipment can be used by a team of firefighters, each carrying a separate supply of the foam concentrate. One team member, the nozzle man, can fight a fire until his supply of concentrate is almost exhausted. At that time the supply hose extending from the jacket to the nozzle is detached, and another team member, the hose man, wearing a similar jacket can attach his supply hose to the nozzle to continue the task of the prior nozzle man, relieving him to go back and replenish his supply. This teamwork procedure enables a more or less continuing application of foam to the fire.
Like all of the above discussed systems, the body mounted foam concentrate must be mixed with water at the fire scene. This is done by using water made available at the fire scene by usual fire hoses connected to a suitable water source.
Mixture of the water and concentrate takes place in a nozzle which forms a part of the body mounted equipment. Water passes through the nozzle at a relatively high rate of flow, developing a reduced pressure in the foam concentrate supply line. This draws foam concentrate into the nozzle where it is mixed with the water and aerated.
The nozzle can be operated to use water or any other fluid, if desired.
Some versions of the third type of body mounted equipment are worn on the back in the form of a depending bag or back pack. These are difficult to maintain in position because the weight and volume of the contained foam concentrate tends to shift, particularly in moving through confined spaces, and this makes it fatiguing for an individual to carry all of the weight on his or her back.
Other body mounted applicators are shoulder mounted to alleviate this problem. Several take the form of a two-piece vest or jacket which is worn over the shoulders and extends down across the front and back of the wearer.
The manufacture and assembly of such a multi-part jacket is relatively expensive, tedious and labor intensive because it involves two separate front and back sections or portions that have to be connected by front and back straps or the like. Also, there is additional expense and complexity arising from the fact that the two separate reservoirs or bladders of the separate portions have to be specially bonded, sewn or formed in place to be waterproof, and the separate portions interconnected to enable emptying of the bladders through a common drain port.
In one embodiment of the prior art such interconnection is provided by a flexible external hose that extends between the two portions. This enables the concentrate to flow into the portion having the drain port, but the external location of the hoses exposes them to significant wear and tear, and possible entanglement with associated equipment or structures encountered in fighting the fire.
Each of the portions of a two piece jacket are relatively heavy when filled with concentrate, and they tend to shift in position when restrained primarily by separate neck or shoulder straps. This type of arrangement is disclosed in U.S. Pat. No. 5,137,094 (Broussard). Unwanted shifting of the weight and center of gravity is an important consideration since fighting fires is extremely tiring and any unbalanced or poorly distributed foam concentrate makes the job of carrying the concentrate that much more fatiguing. The extra exertion required could mean that the fire fighter becomes prematurely fatigued to the point that he or she is taken off the fire, or worse, becomes incapable of escape from rapidly developing hot spots or fire storms.
In summary, portable foam applicators of the prior art typically lack one or more features that are important for optimum performance, such as a high capacity, unitary foam concentrate internal storage bladder or the like, a unitary or one-piece jacket or vest, a self-educting foam nozzle, a foam concentrate ratio controller, and easily controllable dispersion means for applying the foam to a fire. The equipment must also be lightweight, easily donned, capable of being rapidly filled and evenly emptied, possess optimum or proper weight balance, and be made of state-of-the-art fireproof material.
According to the present invention, a portable foam applicator is provided in the form of a one-piece or unitary vest or jacket having front and back portions adhered or bonded together at their edge margins to form heat reflective exterior surfaces and leakproof interior surfaces which define an internal chamber or bladder to hold foam concentrate.
In addition to the edge margin bonds, a pair of elongated, laterally spaced apart, and vertically extending bonds are provided inwardly of the edge margins. These secure the front and back portions together at the bonds, constitute barriers to any sudden lateral displacement or sloshing of the contained foam concentrate which might cause sudden changes in the distribution of the weight of the foam concentrate in the jacket. .
An interior foam concentrate pickup hose is installed within the jacket bottom for extension along its bonded inside perimeter. The hose includes a number of openings along its length to permit foam concentrate to flow from the jacket interior or bladder into the hose.
The discharge extremity of the inner pickup hose is attached or bonded to a jacket fitting, and an exterior pickup hose is connected to the fitting to accept concentrate from the interior pickup and carry it to the exterior of the jacket and through a ratio controller mounted to the exterior pickup hose. The ratio controller is operative to establish the desired percentage of concentrate to feed water. Fire conditions change and a control element on the ratio controller can be quickly adjusted to select the optimum one of various concentrate percentages.
The jacket of the present invention includes a nozzle which is supplied with feed water by a fire hose or the like. The feed water flows rapidly through the nozzle body and develops a negative pressure at the exterior pickup hose sufficient to draw concentrate from the jacket interior, through the ratio controller, through a feed or shut-off valve downstream of the ratio controller, and into the nozzle so that the concentrate and water are mixed and aerated to provide the desired foam.
Other features and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings which illustrate, by way of example, the features of the invention.